结构高度对高耸结构振型贡献率的影响研究

发布时间：2018-11-10 11:02

【摘要】：结构的高阶振型对超高墩桥梁和烟囱类高耸结构的地震响应有较大影响,目前对高耸结构地震响应特性的认识还不够深入。为此,根据高耸结构简化计算模型,推导了高耸结构单阶振型贡献率和累积振型贡献率理论计算公式,并通过有限元模型进行了对比验证,研究了结构高度对结构振型贡献率的影响规律。研究结果表明:结构高度对底部剪力振型贡献率的影响最大,对底部弯矩振型贡献率的影响次之,对结构顶部位移的振型规律性影响最小。结构底部剪力和底部弯矩的第1阶振型贡献率随结构高度的增加先呈现出明显降低,后趋于稳定的变化趋势;而第2阶振型的单阶振型规律性呈现出先随墩高增加而增加,后有所降低的趋势。结构底部剪力和底部弯矩的前n阶振型累计贡献率随结构高度的增加而降低。
[Abstract]:The high-order modes of structures have great influence on the seismic responses of bridges with super-high piers and tall chimney structures. At present, the understanding of seismic response characteristics of high-rise structures is not enough. Therefore, according to the simplified calculation model of high-rise structure, the theoretical calculation formulas of single-order mode contribution rate and cumulative mode contribution rate of high-rise structure are derived, and compared with the finite element model. The influence of structure height on the contribution rate of structure mode is studied. The results show that the height of the structure has the greatest influence on the contribution rate of the bottom shear vibration mode, followed by the contribution rate of the bottom bending moment mode, and the least influence on the vibration pattern regularity of the top displacement of the structure. The contribution rate of the first order vibration mode of the bottom shear force and the bottom bending moment of the structure decreases obviously with the increase of the height of the structure and then tends to change steadily. However, the regularity of the second order mode increases first with the increase of pier height, and then decreases. The cumulative contribution rate of the first n-order vibration modes of the bottom shear force and the bottom bending moment of the structure decreases with the increase of the height of the structure.
【作者单位】：北京工业大学建筑工程学院;
【分类号】：TU973;U441.3

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